We will complete the gel-electrophoretic comparison of a large number of variant human hemoglobins under various conditions of electrophoresis to determine the relationship between the chemical substitution, its location in the 3-dimensional molecule, and its electrophoretic mobility. We will extract and partially purify a large number of variant lac repressor molecules from E. coli and then subject them to the variant conditions of electrophoresis to establish a similar relationship for this molecule that has over 100 known amino acid substitutions. Finally, we are producing radio-labelled bacteriophage T4 strains carrying various amino acid substitutions for the lysozyme molecule. These labelled molecules can then be used in a gel system to establish the relationship between electrophoretic mobility and amino acid substitution in this molecule.